If I have AT&T, will the iPhone 4S work in areas of CDMA coverage only?

Question

The new iPhone 4S has 2 antennas: both GSM and CDMA. Is there a chance that if I, who am an AT&T customer, buy one of these, that I would be able to use it in areas that are CDMA only? AT&T is GSM only. I have two locations out of town that I frequently visit that have ZERO GSM / AT&T coverage, but get full coverage to Verizon and US Cellular, both CDMA networks.